Does Circadian-Activity-Rhythm Architecture Predict Future Cognitive Decline?

To determine whether circadian activity rhythms, as measured by wrist actigraphy, are prospectively associated with incident dementia or mild cognitive impairment (MCI), researchers tracked 1282 cognitively normal, community-dwelling women (mean age, 83). Participants underwent wrist actigraphy at baseline and a comprehensive cognitive assessment about 5 years later, with cognition characterized as normal or meeting criteria for MCI or dementia.

An actigraph, worn like a wristwatch on the nondominant upper limb, is an accelerometer, capturing movement data. The data reflect relative physical activity over time. The more movement a subject exhibits per minute, the higher the value (amplitude) of the signal during that minute. The investigator…